A wide variety of medical techniques and instruments have been developed for diagnosis and/or treatment within a patient's body, such as within a patient's Gastrointestinal (GI) tract. Endoscopic Mucosal Resection (EMR), Endoscopic Sub-mucosal Resection (ESR), Polypectomy, Mucosectomy, etc., are minimally invasive treatment methods for both malignant and non-malignant lesions. Endoscopic medical procedures, such as, for example, EMR, may be used to excise sessile adenomas or other unwanted tissue (i.e., tumors attached to a bodily surface) from the surface of an anatomical lumen. Such procedures often require the resection of one tissue plane while leaving an underlying tissue plane intact. Commonly, snares, designed as loops, have been used during such medical procedures, for resecting tissue from a target site. However, the conventional snares have a tendency to slip off the targeted tissue, and often require repeated efforts to capture the tissue before the resection procedure(s) can be successfully performed. Slippage may increase the length and cost of the procedure and decrease the efficiency.
Conventionally, a downward force on the snare is applied in an effort to improve traction between the snare and the unwanted or target tissue. This downward force is usually limited due to a lack of stiffness in the snare loop, however, causing the distal end of the snare loop to deflect away from the targeted tissue, thereby leading to improper placement of the snare. To control the deflection, the downward force may continue to be applied or it may be increased until the tissue is snared. Continued or increased applied force increases the possibility of accidentally damaging surrounding tissues (in particular underlying tissue layers, such as, e.g., the muscularis), as well as increasing the time and effort required to complete a procedure. Furthermore, it may sometimes be difficult to apply the necessary downward forces due to geometric and physical limitations.